I can't seem to put on or lose any sort of weight. If I eat more and don't exercise, I turn into a space heater to burn off the energy. If I do exercise, all the energy is burnt. Even if I do extra muscle training in my spare time (push ups, sit ups, squats), it doesn't seem to make much of a difference.

Having said that, I don't really want to bulk up too much. I'm quite happy with my speed.

I can't seem to put on or lose any sort of weight. If I eat more and don't exercise, I turn into a space heater to burn off the energy. If I do exercise, all the energy is burnt. Even if I do extra muscle training in my spare time (push ups, sit ups, squats), it doesn't seem to make much of a difference.

Having said that, I don't really want to bulk up too much. I'm quite happy with my speed.

Good lord. I see why strength trainers get really snappy. That said, I can appreciate where you're coming from.

First, the answer should be apparent from your statements: you should eat a LOT more, and you should exercise. That way, you'll gain weight, largely in the form of muscle. In particular, I like the Starting Strength program, but any program with compound barbell lifting (5x5, Westside for skinny bastards, GOMAD, Texas method, to name a few) will do you good.

Second, it's a huge misconception that lifting weights will make you slower. If you're gaining muscle, you'll move faster (to a point, anyway).

Ask any of the more experienced folk to confirm this if you'd like. I'm under the impression that this is the consensus for experienced martial artists.

Thanks for the advice.
Do you have any good links on how I should go about building a diet/eating regime? I tend to eat until I'm quite full, but still end up (sometimes) snacking later on (more often drinking a bit of water to belay the hunger).

I currently have apps on my phone that I'm using to build my strength up to do X number of push ups/sit ups/squats in a row (sit ups, at least. Haven't started the others yet).

Follow it. All of it. Starting strength is among their recommendations, I would also recommend it.

I currently have apps on my phone that I'm using to build my strength up to do X number of push ups/sit ups/squats in a row (sit ups, at least. Haven't started the others yet).

No. Again,

any program with compound barbell lifting (5x5, Westside for skinny bastards, GOMAD, Texas method, to name a few) will do you good.

Look, if you really want some good strength for martial arts, you may have to get a bit fat for a while. You'll lose your six pack (you can't fool me, I was your height and weight before I started, I liked my pathetic six pack too) for a few months. Deal with it; it's not a good indication of strength anyway. Once you get heavier (probably at least 70kg), you can cut the fat, and you'll have your beloved six pack again. Besides which, if you put on that muscle, it'll stretch your skin out more, making the six pack more pronounced.

Eating more will simply make you fatter, not bigger in the sense that you want. Good site: http://www.scoobysworkshop.com/index.htm A lot of misinformation out there so be careful and be sure to consult professionals before dedicating yourself to anything.